Proper inheritance rotation
You need to shear the vertices / edge loops.

Select the edges/vertices in edit mode.

Press CtrlShiftAltS to go into the shear operation.During the operation you can press X or Y to constrain it to the respective axes. In my example I enter the number -1:

CtrlShiftAltS, Y, 1, -

After that simply extrude in the X direction then scale it to zero along the x axis.